ELSEVIER Journal of Organometallic Chemistry 547 (1997) 121-128 Selective cleavage of a P-N bond promoted by alcohols in cis-[Cl 2 M{ S-tPh, P)2 NC( H) t R’)(R”) >] complexes (M = Pd, Pt) X-ray crystal structure of h ,OMe) { S-Ph 2 PN( H) C(H) ( Me)( Phj >] ~0.75MeOH Angel Badia, Lamy R. Falvello, Rafael Navarro * , Esteban P. Urriolabeitia Depmtotttento de Qtthica Ittor~&tica. Ittstimto de Ciencia de Mareriahs de Am&. Unit ersidad de iirrugora- Comejo Sttperior de Int twigmimes Cietttijkas. 50009 ibragox, Spain Received 16 December 1996 Abstract Tbe reaction of MCl,(thtJ, (M = Pd. Pt: tht = tetrahydrothiophene) with S-(Pb,PJ,N-CtHXMeXPhJ f.QteapJ or S-&‘b2P)2N- C(HXCH2Pi%C0,MeJ (S-plap) results in the formation of the neutral tnononuclear derivatives cis-‘Cl$lfSpeapJ] (M = Pd. 1, Pt 3) or cis-[Ci,M(S-plap)] (M = Pd 2. Pt 4) in which the chiral diphosphamne ligands are /‘.I”-chelate 1. Complexes 1-4 re;trr with linear alcohols ROH (R = Me, Et, “Pr: refhtx temperature) resulting in the selective cleavage of only one of the P-N bonds of tbe diphosphazane group and formation of the neutral mononuclear derivatives cis-[C12M(PPh20RXS~2PN(H~(HXKXR”))] (K = ;Me. K’=Ph:R=Me,M=PdS.Pt7:R=Et,M=Pt9:R=”P;,M=Pt10:R=CH,CH,OH,M=Pt11:andK=CH,Ph,R”=CO~hiIe. R = Me: M = Pd 6. Pt 8). The cleavage of the remaining P-N bond was not observed, even at long reaction times, suggesting that the disappearance of the stetic constraint in the four-membered metallacycles l-4 could be responsible for tbe observed reactivity. In spite of this, no reaction tahes place between 1-4 and branched alcohols such as 2-propanol. 2-methyl-2-propanoi or 2-methyl-I-butat~i. ttor with water or weak acids. The characterization of all of these complexes has been carried out through spectroscopic methods and tbmugb the determination of the single-crystal X-my structure of cis-[C12~PPh,0MeXSPh,PN(HKT(HXMeX~)}]. 0.75MeOH. 8 1997 Ekvier Science S.A. 1. Introduction The diphosphittoanine or diphosphazane ligands (PX2J2N-R (X = halirle, alkyl, aryl, alkoxy or aryloxy groups; R = H, alkyl) have attracted the interest of the chemist only some years ago, but this interest has grown very rapidly due to the proved versatility of this class of ligands [l]; the wide range of substituents on both the phosphorus and nitrogen atoms allows a subtle modulation of the electronic and steric properties of these ligands, resulting in significant changes in their coordination behaviour, in the structural parameters of the resulting complexes and in their subsequentreactiv- ity 111. * Corresponding author. On following our recent reports on the coordination chermstrr of diphosphazanes [2,3], we have now fo- cused our attention on the chiral derivatives ( -J-N, N- bis(diphenylphosphino)-S-u-phenylethylamine (S- @h,P)2NC(HXMeXPh) or S-peap) and ( -I-N.N- bis(diphenylphosphino)-S-o-phenylalanine methyl ester (S-G%, P$ NCfHWCHI PhXCO, Me) or S-plap), which up to the present have scarcely been studied 14-61. In this paper we report the synthesis of tire neutral Pd” and Pt” derivatives cis-[C12Mfdiphos)] @@ros = S-peap, S-plap), in which the diphosphazane acts as a P ,p’-chelate, and their reactivity towards protic sol- vents such as alcohols, water or weak acids. In accord with the we:i known hydrolytic instability of the P-N bonds of the diphosphazanes 17-91, even when they ate coordinated [ lO- 121, we have found an interesting reac- tivity of cis-[Cl,M(diphos)] towards linear akoh& 0022-328X/97/$17.00 0 1997 Elsevier Science S.A. All rights reserved. Pli SOO22-328X(97)00206-4